package com.saintdan.framework.component;

import java.io.IOException;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.springframework.core.Ordered;
import org.springframework.core.annotation.Order;
import org.springframework.stereotype.Component;

/**
 * Cross domain filter.
 *
 * @author <a href="http://github.com/saintdan">Liao Yifan</a>
 * @date 3/22/16
 * @since JDK1.8
 */
@Component
@Order(Ordered.HIGHEST_PRECEDENCE)
public class SimpleCORSFilter implements Filter {

  public SimpleCORSFilter() {}

  @Override public void init(FilterConfig filterConfig) {}

  @Override public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain) throws IOException, ServletException {
    HttpServletResponse response = (HttpServletResponse) res;
    HttpServletRequest request = (HttpServletRequest) req;
    response.setHeader("Access-Control-Allow-Origin", "*");
    response.setHeader("Access-Control-Allow-Methods", "POST, GET, OPTIONS, PUT, DELETE");
    response.setHeader("Access-Control-Max-Age", "3600");
    response.setHeader("Access-Control-Allow-Headers", "x-requested-with, authorization");

    if ("OPTIONS".equalsIgnoreCase(request.getMethod())) {
      response.setStatus(HttpServletResponse.SC_OK);
    } else {
      chain.doFilter(req, res);
    }
  }

  @Override public void destroy() {}
}
